Genetic variants that perturb reproductive behavior in Drosophila will be analyzed. These single-gene mutants and genetic mosaics bear directly on the control of this higher-order behavior, or - for a subset of the genetic variants - they influence reproduction in a dramatic fashion, though the mutants were isolated on other criteria. Mutants with altered courtship wing vibration, and a mutant with heightened male-male interactions and aberrant pheromone production, will be analyzed with genetic mosaics, to determine which tissues are affected by the respective mutations. Mutants of acetylcholine metabolism will be studied in mosaics, to ask which tissues in the fly's central nervous system - if neurochemically lesioned - lead to specific alterations in quantifiable aspects of reproduction. Circadian rhythm mutants have been found to affect particular components of courtship, regarding time-frames of minutes and second; and these mutants will be studied in mosaics to determine if the tissues controlled by this gene with respect to diurnal fluctuations (the brain) are the same parts of the animal that the gene affects with regard to reproductive parameters. Conditioned behavior is involved in certain features of courtship, as shown by the effects of a "memory" mutant on male-female interactions. Additional learning and memory mutants will be tested, to see if they too will alter a variety of courtship phenomena in which effects of previous experience are suspected.